but this is not a good way of storing matrix data into coll ,as if you will provide more DOTS onto one column , your coll will store only the last DOT . as you are using matrix column index as a storing index in coll . you cant have more than one index of the same kind inside coll .
you need to figure out how to format that data to separate your index/column storage .
can you use Dict for it ? it might be easier perhaps .
pattr and preset will both work with matrixctrl. if the dots are on/off (no intermediate stages) use preset, because there's no extra file to deal with (unless you want to store additional banks of presets). If you want interpolation, like the matrixctrl cells represent volume levels or something, then use pattr.